Technology Roadmap_ Solar Photovoltaic Energy-6110171e

Technology RoadmapSolar photovoltaic energy

2035 2040

2045

2050

DisclaimerThis report is the result of a collaborative effort between the international energy agency (iea), its member countries and various consultants and experts worldwide. Users of this report shall make their own independent business decisions at their own risk and, in particular, without undue reliance on this report. Nothing in this report shall constitute professional advice, and no representation or warranty, express or implied, is made in respect of the completeness or accuracy of the contents of this report. The iea accepts no liability whatsoever for any direct or indirect damages resulting from any use of this report or its contents. a wide range of experts reviewed drafts, however, the views expressed do not necessarily represent the views or policy of the iea or its individual member countries.

The iNTerNaTioNal eNergy ageNcyThe international energy agency (iea), an autonomous agency, was established in November 1974. its mandate is two-fold: to promote energy security amongst its member countries through collective response to physical disruptions in oil supply and to advise member countries on sound energy policy.

The iea carries out a comprehensive programme of energy co-operation among 28 advanced economies, each of which is obliged to hold oil stocks equivalent to 90 days of its net imports.

The agency aims to:

secure member countries access to reliable and ample supplies of all forms of energy; in particular, through maintaining effective emergency response capabilities in case of oil supply disruptions.

Promote sustainable energy policies that spur economic growth and environmental protection in a global context particularly in terms of reducing greenhouse-gas emissions that contribute to climate change.

improve transparency of international markets through collection and analysis of energy data.

support global collaboration on energy technology to secure future energy supplies and mitigate their environmental impact, including through improved energy efficiency and development and deployment of low-carbon technologies.

Find solutions to global energy challenges through engagement and dialogue with non-member countries, industry, international organisations and other stakeholders.

iea member countries are: australia, austria, Belgium, canada, the czech republic, Denmark, Finland, France, germany, greece, hungary, ireland, italy, Japan, Korea (republic of), luxembourg, the Netherlands, New Zealand, Norway, Poland, Portugal, the slovak republic, spain, sweden, switzerland, Turkey, the United Kingdom and the United states. The european commission also participates in the work of the iea.

1Foreword

ForewordCurrent trends in energy supply and use are patently unsustainable economically, environmentally and socially. Without decisive action, energy-related emissions of CO2 will more than double by 2050 and increased oil demand will heighten concerns over the security of supplies. We can and must change our current path, but this will take an energy revolution and low-carbon energy technologies will have a crucial role to play. Energy efficiency, many types of renewable energy, carbon capture and storage (CCS), nuclear power and new transport technologies will all require widespread deployment if we are to reach our greenhouse gas emission goals. Every major country and sector of the economy must be involved. The task is also urgent if we are to make sure that investment decisions taken now do not saddle us with sub-optimal technologies in the long term.

There is a growing awareness of the urgent need to turn political statements and analytical work into concrete action. To spark this movement, at the request of the G8, the IEA is developing a series of roadmaps for some of the most important technologies. These roadmaps provide solid analytical footing that enables the international community to move forward on specific technologies. Each roadmap develops a growth path for a particular technology from today to 2050, and identifies technology, financing, policy and public engagement milestones that need to be achieved to realise the technologys full potential.

Roadmaps also include special focus on technology development and diffusion to emerging economies.International collaboration will be critical to achieve these goals.

While its use is small today, solar photovoltaic (PV) power has a particularly promising future. Global PV capacity has been increasing at an average annual growth rate of more than 40% since 2000 and it has significant potential for long-term growth over the next decades. This roadmap envisions that by 2050, PV will provide 11% of global electricity production (4 500 TWh per year), corresponding to 3 000 gigawatts of cumulative installed PV capacity. In addition to contributing to significant greenhouse gas emission reductions, this level of PV will deliver substantial benefits in terms of the security of energy supply and socio-economic development. Achieving this target will require a strong and balanced policy effort in the next decade to allow for optimal technology progress, cost reduction and ramp-up of industrial manufacturing. This roadmap also identifies technology goals and milestones that must be undertaken by different stakeholders to enable the most cost-efficient expansion of PV. As the recommendations of the roadmaps are implemented, and as technology and policy frameworks evolve, the potential for different technologies may increase. In response, the IEA will continue to update its analysis of future potentials, and welcomes stakeholder input as the roadmaps are taken forward.

Nobuo TanakaExecutive Director

2 Technology Roadmaps Solar photovoltaic energy

AcknowledgementsThis publication was prepared by the IEAs Renewable Energy Division. It was developed under the lead of Paolo Frankl, Head of the IEA Renewable Energy Division (RED) and Stefan Nowak, Chair of the IEA Implementing Agreement Photovoltaic Power systems (PVPS) Executive Committee. Other co-authors were Marcel Gutschner, Stephan Gnos (Nowak Energie & Technologie Ltd) and Tobias Rinke (IEA/RED). Many other IEA colleagues have provided important contributions, in particular Tom Kerr, Steven Lee, David Elzinga, Uwe Remme, Emi Mizuno, Cedric Philibert, Hugo Chandler and Zuzana Dobrotkova. Tom Kerr also significantly contributed to the final editing of the document. Energetics, Inc. provided editorial comments.

This work was guided by the IEA Committee on Energy Research and Technology. Its members provided important review and comments that helped to improve the document. This roadmap would not be effective without all of the comments and support received from the industry, government and non-government experts and the members of the PVPS Implementing Agreement, who attended the meetings, reviewed and commented on the drafts, and provided overall guidance and support for the roadmap. The authors wish to thank all of those who participated in the meetings and commented on the drafts. The resulting roadmap is the IEAs interpretation of the workshops, with additional information incorporated to provide a more complete picture, and does not necessarily fully represent the views of the workshop participants. A full list of workshop participants and reviewers is included in Annex III.

For more information on this document, contact:

Paolo Frankl, IEA SecretariatTel. +33 1 4057 6591 Email: [email protected]

3Key findings

Key findings Solar PV power is a commercially available and

reliable technology with a significant potential for long-term growth in nearly all world regions. This roadmap estimates that by 2050, PV will provide around 11% of global electricity production and avoid 2.3 gigatonnes (Gt) of CO2 emissions per year.

Achieving this roadmaps vision will require an effective, long-term and balanced policy effort in the next decade to allow for optimal technology progress, cost reduction and ramp-up of industrial manufacturing for mass deployment. Governments will need to provide long-term targets and supporting policies to build confidence for investments in manufacturing capacity and deployment of PV systems.

PV will achieve competitive parity with the power grid by 2020 in many regions. As grid competitiveness is achieved, the policy framework should evolve towards fostering self-sustained markets, with the progressive phase-out of economic incentives, but maintaining grid access guarantees and sustained R&D support.

As PV matures into a mainstream technology, grid integration and management and energy storage become key issues. The PV industry, grid operators and utilities will need to develop new technologies and strategies to integrate large amounts of PV into flexible, efficient and smart grids.

Governments and industry must increase R&D efforts to reduce costs and ensure PV readiness for rapid deployment, while also supporting longer-term technology innovations.

There is a need to expand international collaboration in PV research, development, capacity building and financing to accelerate learning and avoid duplicating efforts.

Emerging major economies are already investing substantially in PV research, development and deployment; however, more needs to be done to foster rural electrification and capacity building. Multilateral and bilateral aid organisations should expand their efforts to express the value of PV energy in low-carbon economic development.

Key actions in the next ten years

Provide long-term targets and supporting policies to build confidence for investments in manufacturing capacity and deployment of PV systems.

Implement effective and cost-efficient PV incentive schemes that are transitional and decrease over time so as to foster innovation and technological improvement.

Develop and implement appropriate financing schemes, in particular for rural electrification and other applications in developing countries.

Increase R&D efforts to reduce costs and ensure PV readiness for rapid deployment, while also supporting longer-term innovations.


Key findings 3

Introduction 5

The rationale for PV 5

The purpose of the roadmap 6

PV status today 7

Technology performance and cost 7

Market trends 9

Research and development 11

Vision for PV deployment and CO2 abatement potential 13

Electricity generation and cumulative installed capacity 13

Applications and market end-use sectors 17

Cost reduction goals 18

PV market deployment and competitiveness levels 19

CO2 emissions reduction 21

Technology development: Strategic goals and milestones 22

Technology trends 22

Specific technology goals and R&D issues 23

Policy frameworks: Roadmap actions and milestones 27

Regulatory framework and support incentives 27

Market facilitation and transformation 29

Technology development and RD&D 30

International collaboration 32

Conclusion: Actions for stakeholders and next steps 35

Appendix I. References and roadmaps consulted 37

Appendix II. List of relevant websites 39

Appendix III. List of workshop participants and reviewers 40

Appendix IV. Abbreviations, acronyms and units 42

Table of Contents

5Introduction

IntroductionThere is a pressing need to accelerate the development of advanced clean energy technologies in order to address the global challenges of energy security, climate change and sustainable development. This challenge was acknowledged by the Ministers from G8 countries, China, India and South Korea, in their meeting in June 2008 in Aomori, Japan where they declared the wish to have IEA prepare roadmaps to advance innovative energy technology.

We will establish an international initiative with the support of the IEA to develop roadmaps for innovative technologies and co-operate upon existing and new partnerships, including CCS and advanced energy technologies. Reaffirming our Heiligendamm commitment to urgently develop, deploy and foster clean energy technologies, we recognise and encourage a wide range of policy instruments such as transparent regulatory frameworks, economic and fiscal incentives, and public/private partnerships to foster private sector investments in new technologies.

To achieve this ambitious goal, the IEA has undertaken an effort to develop a series of global technology roadmaps covering 19 technologies. These technologies are divided among demand side and supply side technologies. Our overall aim is to advance global development and

uptake of key technologies to reach a 50% CO2 emission reduction by 2050 by having the IEA leading the development of energy technology roadmaps under international guidance and in close consultation with industry. The roadmaps will enable governments, industry and financial partners to identify steps needed and implement measures to accelerate required technology development and uptake.

This process starts with providing a clear definition and elements needed for each roadmap. The IEA has defined its global technology roadmap accordingly:

a dynamic set of technical, policy, legal, financial, market and organisational requirements identified by the stakeholders involved in its development. The effort shall lead to improved and enhanced sharing and collaboration of all related technology-specific RDD&D information among participants. The goal is to accelerate the overall RDD&D process in order to deliver an earlier uptake of the specific technology into the marketplace.

Each roadmap identifies major barriers, opportunities, and policy measures for policy makers and industry and financial partners to accelerate RDD&D efforts for specific clean technologies on both a national and international level.

Solar energy is the most abundant energy resource on earth. The solar energy that hits the earths surface in one hour is about the same as the amount consumed by all human activities in a year. Direct conversion of sunlight into electricity in PV cells is one of the three main solar active technologies, the two others being concentrating solar power (CSP) and solar thermal collectors for heating and cooling (SHC). Today, PV provides 0.1% of total global electricity generation. However, PV is expanding very rapidly due to dramatic cost reductions. PV is a commercially available and reliable technology with a significant potential for long-term growth in nearly all world regions. In the IEA solar PV roadmap vision, PV is projected to provide 5% of global electricity consumption in 2030, rising to 11% in 2050.

Achieving this level of PV electricity supply and the associated, environmental, economic and societal benefits will require more concerted policy support. Sustained, effective and adaptive incentive schemes are needed to help bridge the gap to PV competitiveness, along with a long-term focus on technology development that advances all types of PV technologies, including commercially available systems and emerging and novel technologies.

The rationale for PV


This roadmap provides the basis for greater international collaboration and identifies a set of effective technology, economic and policy goals and milestones that will allow solar PV to deliver on its promise and contribute significantly to world power supply. It also identifies the critical window of the next decade, during which PV is expected to achieve competitiveness with the power grid retail prices (grid parity) in many regions. Achieving grid parity will require a strong and balanced policy effort in the next decade to allow for optimal technology progress, cost reduction and ramp-up of industrial manufacturing for mass deployment.

The actions identified in this roadmap are intended to accelerate PV deployment globally. In some markets certain actions have already been achieved, or are underway; but many countries, particularly those in emerging regions, are only just beginning to develop PV power. Accordingly, milestone dates should be considered as indicative of relative urgency, rather than as absolutes.

The roadmap was compiled using inputs from a wide range of stakeholders from the PV industry, power sector, research and development (R&D) institutions, finance, and governments. Two workshops were held to identify technological and deployment issues, and a draft roadmap was subsequently circulated to participants and a wide range of additional reviewers.

This roadmap is informed by a number of existing regional and national roadmaps, including:1

The European Unions Strategic Energy Technology (SET) Plan and the Solar Europe Industry Initiative

The European PV Technology Platforms Implementation Plan for Strategic Research Agenda

The Solar America Initiative (SAI)

Japans PV roadmap towards 2030 (PV2030) and the 2009 update PV2030+

Chinas solar energy development plans

Indias Solar Initiative

Australias Solar Flagship Initiative

This roadmap should be regarded as a work in progress. As IEA analysis moves forward and a new edition of Energy Technology Perspectives is published in 2010, new data will come to light that may provide the basis for updated scenarios and assumptions. More importantly, as the technology, market, power sector and regulatory environments continue to evolve, analyses will need to be updated and additional tasks may come to light.

1 See Appendix II for reference/URL links for all of these efforts.

Solar energy active conversion technologies

Solar photovoltaics (PV), which generates electricity through the direct conversion of sunlight, is one of the three technologies available to use sunlight as an active source. Concentrating solar power systems (CSP) use concentrated solar radiation as a high temperature energy source to produce electrical power and drive chemical reactions. CSP is typically applied in relatively large scale plants under very clear skies and bright sun. The availability of thermal storage and fuel back-up allows CSP plants to mitigate the effects of sunlight variability. Solar heating and cooling (SHC) uses the thermal energy directly from the sun to heat or cool domestic water or building spaces. These three ways of harnessing the sun are complementary, rather than directly competitive, and developers should carefully assess their needs and environment when choosing which solar technology to use. The IEA is publishing a separate CSP roadmap, while SHC will be incorporated into a Low-Carbon/Energy Efficient Buildings Roadmap, to be published in 2010.

The purpose of the roadmap

7PV status today

Technology performance and costPV systems directly convert solar energy into electricity. The basic building block of a PV system is the PV cell, which is a semiconductor device that converts solar energy into direct-current (DC) electricity. PV cells are interconnected to form a PV module, typically up to 50-200 Watts (W). The PV modules combined with a set of additional application-dependent system components (e.g. inverters, batteries, electrical components, and mounting systems), form a PV system. PV systems are highly modular, i.e. modules can be linked together to provide power ranging from a few watts to tens of megawatts (MW).

R&D and industrialisation have led to a portfolio of available PV technology options at different levels of maturity. Commercial PV modules may be divided into two broad categories: wafer based c-Si and thin films. There are a range of emerging technologies, including concentrating photovoltaics (CPV) and organic solar cells, as well as novel concepts with significant potential for performance increase and cost reduction.

PV status today

PV technologies: an overview

Crystalline silicon (c-Si) modules represent 85-90% of the global annual market today. C-Si modules are subdivided in two main categories: i) single crystalline (sc-Si) and ii) multi-crystalline (mc-Si).

Thin films currently account for 10% to 15% of global PV module sales. They are subdivided into three main families: i) amorphous (a-Si) and micromorph silicon (a-Si/c-Si), ii) Cadmium-Telluride (CdTe), and iii) Copper-Indium-Diselenide (CIS) and Copper-Indium-Gallium-Diselenide (CIGS).

Emerging technologies encompass advanced thin films and organic cells. The latter are about to enter the market via niche applications.

Concentrator technologies (CPV) use an optical concentrator system which focuses solar radiation onto a small high-efficiency cell. CPV technology is currently being tested in pilot applications.

Novel PV concepts aim at achieving ultra-high efficiency solar cells via advanced materials and photo-chemical processes. They are currently the subject of basic research.

Detailed information on technologies can also be found in the IEA PVPS Implementing Agreement website www.iea-pvps.org

The large variety of PV applications allows for a range of different technologies to be present in the market, from low-cost, lower efficiency technologies to high-efficiency technologies at higher cost. Note that the lower cost (per watt) to manufacture some of the module technologies,

namely thin films, is partially offset by the higher area-related system costs (costs for mounting and the required land) due to their lower conversion efficiency. Figure 1 gives an overview of the cost and performance of different PV technologies.


Figure 1: Current performance and price of different PV module technologies*

Mod

ule

pric

e (U

SD p

er W

p)

0

1

2

3

4

25%250 W/m2

20%200 W/m2

15%150 W/m2

10%100 W/m2

5%50 W/m2

EfficiencyPerformance

USD600 /m2

USD500 /m2

USD400 /m2

USD300 /m2

USD200 /m2

Moduleprice per m2

OrganicSolar CellsUnder 1%*

Thin FilmsTechnologies

10-15%*

CrystallineSilicon

Technologies85-90%*

ConcentratingPhotovoltaicsTechnologiesUnder 1%*

* percentage share of 2008 market

Note: all values refer to 2008

KEY POINT: There is a wide range of PV cost and performance in todays market.

Conversion efficiency, defined as the ratio between the produced electrical power and the amount of incident solar energy per second, is one of the main performance indicators of PV cells and modules. Table 1 provides the current efficiencies of different commercial PV modules. PV systems can be connected to the utility grid or operated in stand-alone applications. They can also be used in building-integrated systems (BIPV)2 or be ground-mounted, for example, in large-scale, grid-connected electricity production facilities.

2 In this roadmap, the term building-integrated PV systems

is used to indicate both retrofit systems mounted on top of

the existing building structure and fully integrated systems

replacing roof tiles and faade elements.

The investment costs of PV systems are still relatively high, although they are decreasing rapidly as a result of technology improvements and economies of volume and scale. High investment costs, or total system costs, represent the most important barrier to PV deployment today. Total system costs are composed of the sum of module costs plus the expenses for the balance-of-system, including mounting structures, inverters, cabling and power management devices. While the costs of different technology module types vary on a per watt basis (see Figure 1), these differences are less significant at the system level, which also takes into account the efficiency and land-use needs of the technology. Total system costs are sensitive to economies of scale and can vary substantially depending on the type of application.

Table 1: Current efficiencies of different PV technology commercial modules

Wafer-based c-Si Thin films

sc-Si mc-Si a-Si; a-Si/c-Si CdTe CIS/CIGS

14-20% 13-15% 6-9% 9-11% 10-12%

9PV status today

Typical turn-key prices in 2008 in leading market countries ranged from USD 4 000 /kW for utility scale, multi-megawatt applications, to USD 6 000 /kW for small-scale applications in the residential sector.3

Associated levelised electricity generation costs from PV systems depend heavily on two factors: the amount of yearly sunlight irradiation (and associated capacity factor), and the interest/discount rate. PV systems do not have moving parts, so operating and maintenance (O&M) costs are relatively small, estimated at around 1% of capital investment per year. Assuming an

3 The actual range of prices in IEA countries is larger. Best

system prices lower than 3 000 USD/kW were reported

in 2009. At the same time, according to IEA PVPS 2009,

maximum prices for small-scale BIPV systems in 2008 in less

mature PV markets could be much higher.

interest rate of 10%,4 the PV electricity generation costs in 2008 for utility-scale applications ranged from USD 240 /MWh in locations with very high irradiation and capacity factor (2 000 kWh/kW, i.e. a 23% capacity factor), to USD 480 /MWh in sites with moderate-low irradiation (1 000 kWh/kW, corresponding to a capacity factor of 11%). The corresponding generation costs for residential PV systems ranged from USD 360-720 /MWh, depending on the relevant incident solar energy. While these residential costs are very high, it should be noted that residential PV systems provide electricity at the distribution grid level. Therefore they compete with electricity grid retail prices, which, in a number of OECD countries, can also be very high.

4 This roadmap assumes an interest rate of 10%, in

correspondence with the assumption in the IEA Energy

Technology Perspectives study. However, assuming a lower

rate (e.g., 5%) would lead to significantly lower estimates for

generation costs.

Inst

alle

d ca

pac

ity (

MW

p)

0

3 000

6 000

9 000

12 000

15 000

1993

1994

1995

1996

1992

1997

2002

2006

2008

2003

2004

2005

2000

2001

2007

1998

1999

On-grid

Off-grid

Market trendsThe global PV market has experienced vibrant growth for more than a decade with an average annual growth rate of 40%. The cumulative installed PV power capacity has grown from 0.1 GW in 1992 to 14 GW in 2008. Annual

worldwide installed new capacity increased to almost 6 GW in 2008. Figure 2 shows the global cumulative installed capacity of PV for the past two decades.

Figure 2: Cumulative installed global PV capacity

Source : IEA PVPS for those IEA PVPS countries reporting data; estimates for other countries.

KEY POINT: The PV market has experienced rapid growth, with an average annual growth rate of 40%.


Four countries have a cumulative installed PV capacity of one GW or above: Germany (5.3 GW), Spain (3.4 GW), Japan (2.1 GW) and the US (1.2 GW). These countries account for almost 80% of

the total global capacity (Figure 3). Other countries (including Australia, China, France, Greece, India, Italy, Korea and Portugal) are gaining momentum due to new policy and economic support schemes.

Market end-use sectors

There are four end-use sectors with distinct markets for PV:

Residential systems (typically up to 20 kW systems on individual homes)

Commercial systems (typically up to 1 MW systems for commercial office buildings, schools, hospitals, and retail)

Utility scale systems (starting at 1 MW, mounted on buildings or directly on the ground)

Off-grid applications (varying sizes)

These different applications have different system costs and compete at different price levels. Until the mid-1990s, most systems were stand-alone, off-

Figure 3: Solar PV markets in leading countries

Year 2000

800 MW

Year 2004

3 000 MW

Year 2008

more than 14 500 MW

Rest of the world

14% Germany35%

Japan38%

United States13%

Germany15%

Japan44%

United States18%

Rest of the world

23%

Rest of the world

11%

Germany36%

Japan15%United States8%

Spain23%

Italy3%

Korea2%

France1%

China1%

KEY POINT: A handful of countries with strong policy regimes account for 80% of global installed PV capacity; new countries have emerged as important players in the last few years.

11PV status today

grid applications such as telecommunications units, remote communities and rural electricity supply. Since then, the number of grid-connected systems has increased at a rapid pace due to incentive schemes introduced in many countries. The majority of grid-connected systems are installed as BIPV systems. However, ground-mounted large-

scale installations with a generation capacity in the tens of megawatts have gained a considerable market share in recent years. As a result, off-grid PV systems now constitute less than 10% of the total PV market; however, such applications still remain important in remote areas and in developing

countries that lack electricity infrastructure.

Figure 4: Public PV R&D spending in selected countries

2007200620052004200320022001200019991998

Publ

ic P

VRD

exp

endi

ture

s (U

SD m

illio

n)

0

100

200

300

400

500 Other countries US Japan Germany

KEY POINT: Government spending on PV R&D has increased in recent years.

Note: Values in million USD, not corrected for inflation, based on yearly exchange rates.

Source : IEA PVPS.

Research and development Worldwide public expenditures for PV research and development (R&D) have substantially increased over the past decade.5 Public R&D efforts (including pilot and demonstration projects) have doubled in key countries, rising from USD 250 million in 2000 to about USD 500 million in 2007 (Figure 4). Pilot and demonstration projects and

5 While it is difficult to find detailed data on private sector

R&D investment in solar PV, evidence shows that private

investment in the early development phase of solar energy

systems has expanded rapidly during past few years. Solar

energy led all clean energy technology in terms of venture

capital investments in 2008, with USD 5.45 billion of

investment and 88% growth from 2007 (New Energy Finance

[NEF] 2009).

programmes account for about 25% (in 2000) to 30% (in 2007) of these expenditures. R&D efforts are important all along the value chain of energy generation; from raw material production to the manufacturing of modules and balance-of-system components. Solar cell and module research constitutes the largest fraction of the R&D portion, typically 75% of total expenditures (IEA PVPS 2009).


A number of major government and industry R&D efforts aim to make PV a mainstream power source within the next decade, including:6

Within the European Unions SET Plan, the Solar Europe Industry Initiative led by the European Photovoltaic Industry Association (EPIA) proposes three scenarios resulting in three levels of solar share in the electricity market in Europe: 4% for the Baseline scenario, 6% for the accelerated growth scenario and 12% for the paradigm shift scenario. The EPIA is confident about achieving the paradigm shift target, based on the rapid ramp-up of the past decade (average annual growth rate of 40%). The paradigm shift scenario requires a rapid, widespread adoption of smart grid technologies and power storage and further improvements in high quality manufacturing and products all along the PV supply chain.

The European PV Technology Platforms Implementation Plan for Strategic Research Agenda includes dedicated R&D efforts along the value chain in order to accelerate technology development and to achieve new levels of cost-effectiveness.

Through the Solar America Initiative (SAI) from 2007-09, the US Department of Energy has launched a plan for integrated research, development and market transformation of solar energy technologies with the mission to make PV-generated electricity cost-competitive with conventional electricity sources by 2015.

6 See Annex II for a list of references and URLs.

Japans PV roadmaps towards 2030 (PV2030) was developed in 2004 to explore a wide set of R&D options. This effort aims to create viable and sustainable business along the value chain from raw material production to the manufacturing of modules and balance-of-system components. In 2009, the roadmap was revised to PV2030+; it now aims at achieving technology targets three to five years ahead of the schedule set in PV2030.

Australia has recently announced support for the development of 1 000 MW of utility size solar generation, utilising both solar PV and solar thermal. The goal of Australias Solar Flagships initiative is to demonstrate the integration of utility-scale solar generation into a contemporary energy network.

China and India are each pursuing an aggressive solar PV growth strategy, creating a very important industry and setting up ambitious mid-term targets for the domestic market in the multi-GW scale. Brazil is a leading country in the use of PV for rural electrification.

13Vision for PV deployment and CO2 abatement potential

Electricity generation and cumulative installed capacityPV will need to play a significant role in the worlds energy mix in 2050 to help achieve global climate change goals at the lowest cost. According to the BLUE Map scenario described in IEAs Energy Technology Perspectives 2008 (ETP) publication, by 2050, solar power is expected to provide 11% of annual global electricity production, with roughly half generated from PV (6%) and the remaining

from concentrated solar power.7 This roadmap, however, forecasts a more rapid PV deployment than is estimated in the ETP 2008 studyi.e., PV is projected to reach 11% by 2050, almost the double the level estimated in the BLUE Map scenario.

7 Other scenarios in literature indicate contributions well above

the ETP 2008 numbers at world or regional level; see EREC

Greenpeace (2008), EPIA/Greenpeace Solar Generation V

(2008), EPIA Set for 2020 (2009), Grand Solar Plan (2008).

Vision for PV deployment and CO2 abatement potential

Energy Technology Perspectives 2008 BLUE Map Scenario

This roadmap outlines a set of quantitative measures and qualitative actions that represent one global pathway for solar PV deployment to 2050. It builds on the IEA Energy Technology Perspectives (ETP) BLUE Map scenario, which describes how energy technologies may be transformed by 2050 to achieve the global goal of reducing annual CO2 emissions to half that of 2005 levels. The ETP model is a bottom-up MARKAL model that uses cost optimisation to identify least-cost mixes of energy technologies and fuels to meet energy demand, given constraints such as the availability of natural resources. The ETP model is a global fifteen-region model that permits the analysis of fuel and technology choices throughout the energy system. The models detailed representation of technology options includes about 1 000 individual technologies. The model has been developed over a number of years and has been used in many analyses of the global energy sector. In addition, the ETP model was supplemented with detailed demand-side models for all major end-uses in the industry, buildings and transport sectors.

An accelerated outlook is justified by the recent PV market growth (Figure 2) and associated cost reductions the global PV market more than doubled in one year from 2007 to 2008, and system prices fell 40% between 2008 and 2009. This acceleration in the deployment of PV has been triggered by the adoption of PV incentive schemes in an increasing number of countries. As a result of this sort of policy support, this roadmap envisions that PV will achieve grid parity in many countries by 2020. Parity is expected to first be achieved in

those countries having a high solar irradiation level and high retail electricity costs. This roadmap also assumes the continuation of an evolving, favourable and balanced policy framework for market deployment and technology development in many countries on the longer term. If such policies are successfully implemented, by 2050 there will be 3 000 GW of installed PV capacity worldwide, generating 4 500 TWh per year, 11% of expected global electricity supply (Figure 5).


Figure 5: Global PV power generation and relative share of total electricity generation

PV e

lect

ricity

gen

erat

ion

in T

Wh

Rela

tive

PV s

hare

of t

otal

glo

bal

elec

tric

ity g

ener

atio

n

0

1 000

2 000

3 000

4 000

6 000

5 000

0%

2%

4%

6%

8%

12%

10%

2010 2015 2020 2025 2030 2035 2040 2045 2050

ETP Blu

e Map

Scenar

ioIEA Ro

admap

Vision

Scena

rio

Indu

stry S

cena

rio: G

reen

peac

e/EP

IA

Solar

Gen

erat

ion

V ad

vanc

ed

PV electricity generation share for each scenarioScenario

Note: The share of total electricity generation is calculated with the projected world electricity.

Sources: IEA Energy Technology Perspectives 2008, EPIA/Greenpeace Solar Generation V generation of the ETP BLUE Map scenario

(42 300 TWh).

KEY POINT: The roadmap envisions PV providing 11% of global electricity generation by 2050.

The roadmap assumes an average annual market growth rate of 17% in the next decade, leading to a global cumulative installed PV power capacity of 200 GW by 2020.8 This level of PV market growth is justified by the achievement of grid parity predicted to occur in an increasing number of countries during this time. Achieving grid parity (i.e. competitiveness with electricity grid retail prices) will be facilitated in part by policy incentives that support the deployment and decrease overall costs of PV and by measures increasing the cost of other technologies. Accelerated deployment and market growth will in turn bring about further cost reductions from economies of scale, significantly improving the relative competitiveness of PV by 2020 and spurring additional market growth.

8 Note that this value is significantly higher than the ETP 2008

forecast, but significantly lower than industrys goals. For

example, the European SET plan projects 400 GW installed in

Europe by 2020, and an indicative target of 700 GW by 2030.

From 2020 to 2030, an average annual market growth rate of 11% is assumed, bringing global cumulative installed PV capacity to about 900 GW by 2030. At this time, the annual market volume of new installed capacity would be over 100 GW per year. The total cumulative installed PV capacity is predicted to reach 2 000 GW by 2040 and 3 000 GW by 2050, taking into account the replacement of old PV systems. The forecasted global cumulative installed PV capacity according to this roadmap is presented in Figure 6 and compared with the ETP 2008 BLUE Map scenario and other industry scenarios.


KEY POINT: This roadmap sets an accelerated vision for PV growth; other estimates suggest that PV potential could be higher.

Figure 6: Comparison of IEA roadmap vision of global cumulative installed PV capacity to other scenarios

Note: ETP Blue Scenarios capacity was calculated using 1 500 kWh/kW.

Sources: Outcomes of PV Roadmap workshops 2009, IEA Energy Technology Perspectives 2008, EPIA/Greenpeace Solar Generation V.

Tota

l ins

talle

d ca

pac

ity in

GW

p

0

2 000

3 000

4 000

5 000

6 000

1 000

20502040203020202010

ETP Blue M

ap scenarioIEA

Roadma

p vision

scenari

o

Indust

ry sce

nario:

Greenp

eace/E

PIA

Solar G

enerat

ion V

advanc

ed

Emerging economies: rapidly growing PV markets

This roadmap envisions a rapid growth of PV power throughout the world in OECD countries as well as in Asia, and at a later stage in Latin America and Africa. Major economies like China and India have become global solar forces in the past decade, and will remain important market influencers in the decades to come. The potential of PV for distributed generation is very substantial in Latin America and Africa. These world regions may become very important markets in the mid- to long-term. Brazil is a leading country in the use of PV for rural electrification and can play a major role in technology collaboration with developing countries.

Brazil

The main applications of PV technology in Brazil are telecommunications (i.e. microwave repeater stations), rural electrification, water pumping and public lighting in low-income rural communities. Grid-connected PV systems are still in an experimental stage, with a combined power of 22 kWp installed (Varella et al., 2009). In 1995, the Brazilian government launched a programme to promote rural electrification with PV systems, PRODEEM (Programme of Energy Development of States and Municipalities). Approximately 9000 PV systems were installed in the period 1996-2001, with a total of 6 MWp of installed capacity. In 2003, the federal government launched the programme Luz para Todos (Light for All), which aims to supply full electrification in the country by 2010. The programme has an estimated total budget of about USD 2.6 billion funded by the federal government, concessionaires and state governments. A programme for labelling PV equipment and systems was launched in 2003 by INMETRO (Brazilian Institute for Metrology, Standardisation and Industrial Quality) to guarantee the quality of equipment acquired and installed within the Light for All programme. This labelling scheme is currently in force and applies to PV modules, charge controllers, inverters and batteries and is done on a voluntary basis (Varella et al., 2008). The Brazilian PV market is currently dominated by multinationals, and there are no national manufacturers. However, with the support of the government, the Brazilian Centre for Development of Solar PV Energy (CB-Solar), created in 2004, has developed a pilot plant to manufacture cost effective PV modules and silicon solar cells at scale (Moehlecke and Zanesco, 2007).


China

Chinas solar PV industry has been growing rapidly and the country now ranks first in the world in exports of PV cells. Domestic output of PV cells expanded from less than 100 MW in 2005 to 2 GW in 2008, experiencing a 20-fold increase in just four years (Sicheng Wang, 2008). This is the result of a strong demand from the international PV market, especially from Germany and Japan. However, the PV market demand in China remains small, with more than 95% of the countrys PV-cell products exported. In 2008, Chinas cumulative PV installed capacity was 150 MW (National Energy Administration, 2009). Some 40% of this demand is met by independent PV power systems that supply electricity to remote districts not covered by the national grid. Market shares of solar PV for communications, industrial, and commercial uses have also increased. BIPV systems, as well as large-scale PV installations in desert areas, are being encouraged by the Chinese government, which began providing a subsidy of RMB 20 (USD 2.93) per watt for BIPV projects in early 2009. It is likely that the 2010 and 2020 national targets for solar PV (400 MW and 1 800 MW, respectively) announced in 2007 will be significantly increased. Experts predict that Chinese installed capacity could reach 1 GW in 2010 and 20 GW in 2020 (CREIA, 2009).

India

India has a large and diversified PV industry consisting of ten fully vertically integrated manufacturers making solar cells, solar panels and complete PV systems, and around 50 assemblers of various kinds. Together, these companies supply around 200 MW per year of 30 different types of PV systems in three categories rural, remote area and industrial. However, despite this strong industrial base, PV constitutes a small part of Indias installed power generation capacity, with 2.7 MW grid- connected systems and 1.9 MW stand-alone systems in 2008 (Banerjee, 2008). There have been a number of high-level government initiatives that have provided new momentum for PV deployment in India, including:

The 2008 Action Plan on Climate Change included a National Solar Mission that establishes a target of generating 20 GW of electricity from solar energy by 2020; the programme aims to boost annual PV power generation to 1 000 MW by 2017.

In 2008, the Ministry of New and Renewable Energy (MNRE) established a target of 50 MW of capacity by 2012 to be achieved through its Generation Based Incentives (GBI) programme. The GBI includes production incentives for large solar power plants of INR 12 (USD 0.25) per kWh for PV power for up to 50 MW of capacity, subject to a maximum 10 MW in any one state.

The Eleventh Five-Year Plan (2007-12) proposed solar RD&D funding of INR 4 billion (86.4M USD). The Working Group on R&D for the Energy Sector proposed an additional INR 53 billion (1.15B USD) in RD&D for the Eleventh Five-Year Plan, with the two largest topics being: research on silicon production for PV manufacturing (total investment INR 12 billion [259M USD] , including the establishment of a silicon production facility) and research on LEDs (INR 10 billion [216M USD] , also including the establishment of a manufacturing facility).


Applications and market end-use sectors

The relative share of the four market segments (residential, commercial, utility-scale and off-grid) is expected to change significantly over time (Figure 7). In particular, the cumulative installed capacity of residential PV systems is expected to decrease from almost 60% today to less than 40%

by 2050. Figure 7 shows a possible development path for electricity generation of PV systems worldwide by end use sector. The relative shares of PV deployment among the different sectors will vary by country according to each countrys particular market framework.

Figure 7: Evolution of photovoltaic electricity generation by end-use sector

0

1 000

2 000

3 000

3 500

4 000

4 500

500

1 500

2 500

12%

10%

8%

6%

4%

2%

0%

2010 2020 2030 2040 2050

Phot

ovol

taic

ele

ctric

ity

gen

erat

ion

(TW

h p

er y

ear)

Shar

e of

glo

bal e

lect

ricity

gen

erat

ion

(%)

Residential

Commercial

Utility

Off-grid

Share

of gl

obal e

lectric

ity ge

nerat

ion (%

)

Source : IEA analysis based on survey reports of selected countries between 1992 and 2008, IEA PVPS, and IEA 2008 (ETP).

KEY POINT: There will be a shift from residential to larger-scale PV applications over time.

Tables 2, 3 and 4 provide more detailed information on the evolution by sector of global electricity generation, cumulative installed power capacity, and annual market, respectively.

Table 2: Annual PV power generation (TWh) by end-use sector

Annual electricity generation (TWh) 2010 2020 2030 2040 2050

Residential 23 153 581 1244 1794

Commercial 4 32 144 353 585

Utility 8 81 368 910 1498

Off-grid 3 32 154 401 695

Total 37 298 1247 2907 4572

Note that the average electricity generation per kW is 1 300 kWh/kW in the residential sector, 1 450 kWh/kW in the commercial sector,

1650 kWh/kW in the utility sector and 1500 kWh/kW in the off-grid sector.


Table 3: Cumulative installed PV capacity (GW) by end-use sector

PV capacity (GW) 2010 2020 2030 2040 2050

Residential 17 118 447 957 1380

Commercial 3 22 99 243 404

Utility 5 49 223 551 908

Off-grid 2 21 103 267 463

Total 27 210 872 2019 3155

Table 4: Annual global PV market volume (GW) by end-use sector

PV market (GW) 2010 2020 2030 2040 2050

Residential 4.1 18 50 55 53

Commercial 0.7 4 13 17 20

Utility 1.6 8 28 37 44

Off-grid 0.6 4 14 19 24

Market 7 34 105 127 141

Cost reduction goalsWhile the production costs vary among the different PV module technologies, these module-level cost differentials are less significant at the system level, which are expected to converge in the long term. Therefore, this roadmap suggests setting overall cost targets by application (e.g., residential, commercial or utility-scale) rather than for specific PV technologies (e.g., crystalline silicon, thin films, or emerging and novel devices). The roadmap assumes that cost reductions for future PV systems continue along the historic PV experience curve. PV module costs have decreased in the past at a learning rate of 15% to 22%,9 and have seen a corresponding reduction in total system costs for every doubling of cumulative installed capacity. The roadmap adopts a learning rate of 18% for the whole PV system.

9 An experience curve describes how unit costs decline with

cumulative production. The relevant cost decline measure is

given by the progress ratio (P) or the learning rate (L=1-P). A

learning rate of 20% corresponds to a cost reduction by 20%

for each doubling of cumulative production. Sources: Neji

2007, EPIA; Set for 2020; A Mainstream Power Source in Europe

by 2020; 2009

Tables 5, 6 and 7 summarise the cost targets for PV in the residential, commercial, and utility sectors, respectively, in terms of both total turnkey system price (cost per kW installed capacity) and total cost of electricity (cost per MWh energy generated). Such cost targets are the result of the roadmap workshop discussion, based on the Strategic Research Agenda and the Implementation Plan of the European PV Technology Platform (2007, 2009), the Solar America Initiative (DOE 2007), the Japanese PV roadmap towards 2030 / PV2030+ (NEDO 2004, 2009) and the IEA Energy Technology Perspectives 2008.

The primary PV economic goal is to reduce turn-key system prices and electricity generation costs by more than two-thirds by 2030. Turn-key system prices are expected to drop by 70% from current USD 4 000 to USD 6 000 per kW down to USD 1 200 to USD 1 800 per kW by 2030, with a major price reduction (over 50%) already achieved by 2020. Large scale utility system prices are expected to drop to USD 1 800 per kW by 2020 and USD 800 per kW by 2050, and in the best case will lead to long-term levelised generation costs lower than USD 50 /MWh.


Table 5: Cost targets for the residential sector

2008 2020 2030 2050

Typical turn-key system price (2008 USD/kW) 6000 2700 1800 1200

Typical electricity generation costs (2008 USD/MWh)*

2000 kWh/kW 360 160 100 65

1500 kWh/kW 480 210 135 90

1000 kWh/kW 720 315 205 135

Assumptions: Interest rate 10%, technical lifetime 25 years (2008), 30 years (2020), 35 years (2030) and 40 years (2050);

operations and maintenance (O&M) costs 1%.

Table 6: Cost targets for the commercial sector

2008 2020 2030 2050

Typical turn-key system price (2008 USD/kWp) 5000 2250 1500 1000


2000 kWh/kWp 300 130 85 55

1500 kWh/kWp 400 175 115 75

1000 kWh/kWp 600 260 170 110


O&M costs 1%.

Table 7: Cost targets for the utility sector

2008 2020 2030 2050

Typical turn-key system price (2008 USD/kWp) 4000 1800 1200 800


2000 kWh/kWp 240 105 70 45

1500 kWh/kWp 320 140 90 60

1000 kWh/kWp 480 210 135 90


O&M costs 1%.

PV market deployment and competitiveness levelsPV has already achieved competitiveness for a number of products, services and applications. However, the majority of the PV industry output is grid-connected; therefore, the on-grid market will remain the major market segment in the future. Commercial goals for PV are therefore focused on achieving respectively competitiveness with electricity grid retail prices for residential

and commercial PV systems, and with electricity generation costs for utility-scale systems. Since electricity prices and solar irradiation vary from one market place to another it is only possible to identify time ranges for PV competitiveness on a global basis. Three main phases have been envisioned for the commercial development of PV (Figure 8).


Figure 8: PV market deployment and competitiveness levels

KEY POINT: PV is already competitive today in selected off-grid applications, and will achieve competitiveness in three phases.

Elec

tric

ity g

ener

atio

n co

sts

(USD

per

MW

h)

250

150

100

50

300

200

350

400

0

PV utility

PV residential

BLUE Map wholesale electricity costs

BLUE Map retail electricity costs

2 000 kWh/kW

1 500 kWh/kW

2 000 kWh/kW

1 000 kWh/kW

Establishment of PV industrial mass production

Large-scale integration of PV power in the grid

PV systems and power for general purpose use

PV systems and power for general purpose use

1 000

4 000

3 000

2 000

040 TWh/yr 300 TWh/yr

1200 TWh/yr

Supported market growth in increasing number of countries

through 2020

Tangible contribution to power supplyTransition to self-

sustained markets

High penetration of PV out to 2050

Note: PV electricity generation costs are calculated with a 10% discount rate

Ann

ual P

V el

ectr

icity

gen

erat

ion

in te

raw

att-

hour

s (T

Wh/

yr)

1st competitiveness level: PV least cost option in selected

applications

2nd competitiveness level:PV generation costs = retail electricity prices and tariffs

3rd competitiveness level:PV generation costs = wholesale electricity costs

Typical utility system price: USD 4 000/kW

Typical utility electricity generation costs: USD

240/MWh

Utility price: USD 1 800/kW

Costs: USD 105/MWh

Utility price: USD 1 200/kW

Costs: USD 70/MWh

PV capacity: 27 GW

Market: 7 GW/yr

Share of global electricity generation

2010: 0.2%

Share: 1%

Capacity: 200 GW

Market: 34 GW/yrShare: 5%

Market: 105 GW/yr

Capacity: 900 GW

2010 2020 2030


O&M costs 1%.

In the first decade, the annual PV market is expected to increase from 6 GW to 34 GW, to ramp-up into mass-scale industrial production, and to reduce system and generation costs by more than 50%. This will allow PV residential and commercial systems to achieve parity with the distribution grid electricity retail prices in a number of countries characterised by a good solar resource and high conventional electricity retail prices. In a few cases, this is likely to occur before 2015. By 2020 PV generation costs are expected to range from USD 13-26 cents/kWh (commercial systems) to USD 16-31 cents/kWh (residential systems), depending on the site-specific solar irradiation level. These costs are expected to be lower than electricity retail prices in several countries. In the same timeframe, utility PV system will achieve USD 10 cents/kWh, arriving at the edge of competitiveness with wholesale electricity costs in some countries. To achieve these goals, PV will require sustained and consistent policy frameworks and support incentives in many countries during this period.

From 2020 to 2030, this roadmap envisions that PV will advance toward large-scale grid integration, and start to become competitive at a much broader scale. Towards the end of the decade, typical utility PV system generation costs are expected to decrease down to USD 7-13 cent/kWh and PV will become competitive at utility-scale with wholesale electricity prices in some world regions. By that time, commercial and residential systems will become cost-competitive in almost all world regions with reasonable solar irradiation. The annual market/shipment volume will have increased by another factor of three over this decade (hitting the benchmark of 100 GW by 2030), leading to a cumulative installed capacity of almost 900 GW worldwide. During this period, economic incentives should begin to gradually be phased-out while maintaining grid access guarantees and sustained R&D support.


The phase from 2030-2050 will be characterised by the large-scale diffusion of PV systems and power for general purpose uses. System costs will range from USD 800 to USD 1200 /kW depending on the application sector. This will lead to typical generation costs of USD 4.5-9 cent/kWh at the utility scale and of USD 6.5-13.5 cent/kWh at

residential level. The annual market will still grow, although at a slower pace than in the two previous decades. The total cumulative installed capacity will increase up to 3 000 GWp. This will generate an electricity production of approximately 4 500 TWh/year, corresponding to a projected share of around 11% of total world electricity generation.

Total investment needs

Achieving this roadmap, based on the assumed evolution of system costs and the need for PV system replacement, will require a total investment on the order of USD 5 trillion (Figure 9).10

10 While this figure is large, it is only 6% of the total additional

investment needed to achieve the BLUE Map scenario target

of reducing energy sector CO2 emissions 50% by 2050.

Figure 9: PV investments by decade

KEY POINT: Achieving this roadmaps goals will require an investment of USD 5 trillion.

0400

1 6001 200

800

20202010 2030 2040 2050

Inve

stm

ent

cost

s p

er d

ecad

e (U

SD b

illio

n)

CO2 emissions reductionThe deployment of PV will contribute significantly to the reduced carbon intensity of electricity generation. Taking into account the different average CO2 emissions of electricity production mixes in different world regions, and using the BLUE Map scenario average long-term emission reduction coefficients for the power sector, the 4 500 TWh generated by PV in 2050 is expected to save 2.3 Gt of CO2 emissions on an annual basis worldwide, almost twice that predicted in the BLUE Map scenario. This corresponds to approximately 5% of the total avoided CO2 emissions (48 Gt) from all technology areas projected in the ETP 2008 BLUE Map Scenario with respect to the Baseline Scenario. Over the period 2008-2050,

the estimated cumulative savings are around 100 Gt of CO2 (Figure 10).

11

Figure 10: Annual CO2 emissions avoided through PV

11 This takes into account an average operational lifetime of

35 years and the relevant decommissioning and substitution

of old plants.

0500

2 5002 0001 5001 000

20202010 2030 2040 2050CO

2 sav

ing

s (M

t/yr

)

KEY POINT: This roadmaps accelerated use of PV results in emissions reductions of more than 2 Gt CO2 per year by 2050.


Achieving the deployment path outlined in this roadmap will require a significant investment by government and industry in effective technology development and policy implementation.

This section identifies short-, mid- and long-term technology goals and milestones and related key R&D issues.

Technology trendsWith the aim of achieving further significant cost reductions and efficiency improvements, R&D is predicted to continuously progress in improving existing technologies and developing new technologies. It is expected that a broad variety of technologies will continue to characterise

the PV technology portfolio, depending on the specific requirements and economics of the various applications. Figure 11 gives an overview of the different PV technologies and concepts under development.

KEY POINT: Current technologies will co-exist with emerging technologies and novel concepts.

Table 8 summarises a set of general technology targets for PV systems, expressed in terms of (maximum) conversion efficiency, energy-payback time, and operational lifetime. Typical commercial flat-plate module efficiencies are expected to increase from 16% in 2010 to 25% in 2030 with the potential of increasing up to 40% in 2050. Concurrently, the use of energy and materials in the manufacturing process will become significantly more efficient, leading to considerably shortened

PV system energy pay-back times.12 The latter is expected to be reduced from two years in 2010 to 0.75 year in 2030 and below 0.5 year in the long-term. Finally, the operational lifetime is expected to increase from 25 to 40 years.

12 The energy pay-back time is defined as the time needed

for the PV system to repay the energy spent for its

manufacturing.

Technology development: Strategic goals and milestones

Figure 11: Photovoltaic technology status and prospects

Source : IEA PVPS.

0

10%

20%

30%

40%

2020 20302008

Advanced inorganic thin-film

technologies

Organic solar cells

III Emerging

technologies

and novel con

cepts

IV Concen

trating photo

voltaics

I Crystalline silicon tech

nologies:

single crystalline, multi-cr

ystalline, ribbon

II Thin-film technologies

:

cadmium-telluride, copper

-indium/gallium,-diselenide

/disulphide and related II-VI

compounds, thin-film silic

on

Quantum wells, up-down con

verters, intermediate

band gaps, plasmonics, therm

o-photovoltaics, etc

Effic

ienc

y ra

tes

of in

dust

rially

man

ufac

ture

d m

odul

e/pr

oduc

t

23Technology development: Strategic goals and milestones

Table 8: General technology target

Targets (rounded figures) 2008 2020 2030 2050

Typical flat-plate module efficiencies Up to 16% Up to 23% Up to 25% Up to 40%

Typical maximum system energy pay-back time (in years) in 1500 kWh/kWp regime

2 years 1 year 0.75 year 0.5 year

Operational lifetime 25 years 30 years 35 years 40 years

Specific technology goals and R&D issuesCrystalline silicon

Today, the vast majority of PV modules (85% to 90% of the global annual market) are based on wafer-based c-Si. Crystalline silicon PV modules are expected to remain a dominant PV technology until at least 2020, with a forecasted market share of about 50% by that time (Energy Technology Perspectives 2008). This is due to their proven and reliable technology, long lifetimes, and abundant primary resources. The main challenge for c-Si modules is to improve the efficiency and effectiveness of resource consumption through materials reduction, improved cell concepts and automation of manufacturing.

The manufacturing of c-Si modules typically involves growing ingots of silicon, slicing the ingots into wafers to make solar cells, electrically interconnecting the cells, and encapsulating the strings of cells to form a module. Modules currently use silicon in one of two main forms: single- sc-Si

or mc-Si.13 Current commercial single sc-Si modules have a higher conversion efficiency of around 14 to 20%. Their efficiency is expected to increase up to 23% by 2020 and up to 25% in the longer term. Multi-crystalline silicon modules have a more disordered atomic structure leading to lower efficiencies, but they are less expensive (see Table 9 and Figure 1). Their efficiency is expected to increase up to 21% in the long term.

Continuous targeted R&D on sc-Si technologies in public and industrial research with a near-term focus can result in a substantial cost reduction and an associated volume effect, both of which are needed to enhance the competiveness and accelerate the scaling-up of PV in the next decade. The major required R&D efforts for crystalline solar cells are summarised in Table 9.

13 Recently, ribbon technologies have been developed that have

potentially similar efficiencies as mc-Si but a much better

utilisation rate of silicon feedstock. However, this particular

technology has not yet achieved significant market shares.


Table 9: Technology goals and key R&D issues for crystalline silicon technologies

Crystalline silicon technologies

2010 2015 2015 2020 2020 2030 / 2050

Efficiency targets in % (commercial modules)

Single-crystalline: 21%

Multi-crystalline: 17%





Industry manufacturing aspects

Si consumption < 5 grams / Watt (g/W)

Si consumption < 3 g/W Si consumption < 2 g/W

Selected R&D areas

New silicon materials and processing

Cell contacts, emitters and passivation

Improved device structures

Productivity and cost optimisation in production

Wafer equivalent technologies

New device structures with novel concepts

Thin films

Thin films are made by depositing extremely thin layers of photosensitive materials in the micrometre (m) range on a low-cost backing such as glass, stainless steel or plastic. The first thin film solar cell produced was a-Si. Based on early a-Si single junction cells, amorphous tandem and triple cell configuration have been developed. To reach higher efficiencies, thin amorphous and microcrystalline silicon cells have been combined to form micromorph cells (also called thin hybrid silicon cells).14 In the area of II-VI semiconductor compounds, other thin film technologies have been developed, including Cadmium Telluride (CdTe) and Copper-Indium-Gallium-Diselenide (CIGS).

14 Another option currently being researched is the

combination of single-crystalline and amorphous PV cell

technology. The HIT (Heterojunction with Intrinsic Thin layer

cells) technology is based on a crystalline silicon cell coated

with a supplementary amorphous PV cell to increase the

efficiency.

The main advantages of thin films are their relatively low consumption of raw materials, high automation and production efficiency, ease of building integration and improved appearance, good performance at high ambient temperature, and reduced sensitivity to overheating. The current drawbacks are lower efficiency and the industrys limited experience with lifetime performances.

Increased R&D is needed to bring thin film technologies to market and to create the necessary experience in industrial manufacturing and long-term reliability. The most promising R&D areas include improved device structures and substrates, large area deposition techniques, interconnection, roll-to-roll manufacturing and packaging. Table 10 summarises the prospects and key R&D issues for thin film technologies until 2030.

25Technology development: Strategic goals and milestones

Table 10: Technology goals and key R&D issues for thin film technologies

Thin film technologies 2010 2015 2015 2020 2020 2030

Efficiency targets in % (commercial modules)

Thin film Si: 10%

Copper indium gallium (di)selenide (CIGS): 14%

Cadmium-telluride (CdTe): 12%

Thin film Si: 12%

CIGS: 15%

CdTe: 14%

Thin film Si: 15%

CIGS: 18%

CdTe: 15%

Industry manufacturing aspects

High rate deposition

Roll-to-roll manufacturing

Packaging

Simplified production processes

Low cost packaging

Management of toxic materials

Large high-efficiency production units

Availability of manufacturing materials

Recycling of modules

Selected R&D areas Large area deposition processes

Improved substrates and transparent conductive oxides

Improved cell structures

Improved deposition techniques

Advanced materials and concepts

Thin film technologies are in the process of rapid growth. In the last years, thin film production units have increased from pilot scale to 50 MW lines, with some manufacturing units in the GW range recently announced. As a result, thin films are expected to increase their market share significantly by 2020.

II-VI semiconductor thin films

CdTe cells are a type of II-VI semiconductor thin film and have a relatively simple production process, allowing for lower production costs. CdTe

technology has achieved the highest production level of all the thin film technologies. It also has an energy payback time of eight months, the shortest time among all existing PV technologies. For CIGS cells, the fabrication process is more demanding and results in higher costs and efficiencies compared to CdTe cells. Today, CdTe has achieved a dominant position amongst thin film in terms of market share and has a market-leading cost-per watt. However, it is difficult to predict which of the thin film technologies will reach higher market shares in a mid- and long-term perspectives.

Emerging technologies and novel concepts15

Emerging technologies

Emerging PV technologies comprise advanced inorganic thin film technologies (e.g. Si, CIS) as well

15 The label emerging applies to technologies for which

at least one proof-of-concept exists or which can

be considered longer term options that will radically

improve the development of the two established solar cell

technologies crystalline Si and thin film solar cells. The

label novel applies to developments and ideas that can

potentially lead to new innovative technologies.

as organic solar cells. Within the organic cells area, there are different technology branches such as the dye sensitised solar cell (a hybrid approach of an organic cell retaining an inorganic component) and fully organic approaches. Organic solar cells are potentially low cost technologies that are about to make their market entrance for niche applications. Their relevance for energy production in power applications, however, remains to be proven. Another emerging PV technology is based on the concept of thermo-photovoltaics whereby a high efficiency PV cell is combined with a thermal radiation source. This concept could also become relevant for concentrating solar technologies in the future.


Novel PV concepts

Novel PV concepts aim at achieving ultra-high-efficiency solar cells by developing active layers which best match the solar spectrum or which modify the incoming solar spectrum. Both approaches build on progress in nanotechnology and nano-materials. Quantum wells, quantum wires and quantum dots are examples of structures introduced in the active layer. Further approaches deal with the collection of excited charge carriers (hot carrier cells) and the formation of intermediate band gaps. These novel concepts are currently the

subject of basic research. Their market relevance will depend on whether they can be combined with existing technologies or whether they lead to entirely new cell structures and processes. Large market deployment of such concepts if proven successful is expected in the medium to long term. Considerable basic and applied R&D efforts aimed at the mid- to long-term are required in order to further develop these approaches and to ultimately bring them to market in end use applications.

Concentrator technologies (CPV)

All PV technologies described so far are so-called flat-plate technologies which use the naturally available sunlight. As an alternative, direct solar radiation can be concentrated by optical means and used in concentrator solar cell technologies. Considerable research has been undertaken in this high-efficiency approach because of the attractive feature of the much smaller solar cell area required. Low and medium concentration systems (up to 100 suns) work with high-efficiency silicon solar cells. For the highest concentration levels beyond

500 suns, III-V compound semiconductors are being used for the CPV solar cells and efficiencies beyond 40% have been achieved in the laboratory.

The CPV technology is presently moving from pilot facilities to commercial-scale applications. Further R&D efforts are required in optical systems, module assembly, tracking systems, high-efficiency devices, manufacturing and installation. The prospects and key R&D issues for CPV as well as emerging and novel technologies are summarised in Table 11.

Table 11: Prospects and key R&D issues for concentrating PV, emerging and novel technologies

Concentrating PV Emerging technologies Novel technologies

Type of cell High cost, super high efficiency

Low cost, moderate performance

Very high efficiency Full spectrum utilisaton

Status and potential 23% alternating-current (AC) system efficiency demonstrated

Potential to reach over 30% in the medium-term

Emerging technologies at demonstration level (e.g. polymer PV, dye PV, printed CIGS)

First applications expected in niche market applications

Wide variety of new conversion principle and device concepts at lab level

Family of potential breakthrough technologies

Selected R&D areas Reach super high efficiency over 45%

Achieve low cost, high-performance solutions for optical concentration and tracking

Improvement of efficiency and stability to the level needed for first commercial applications

Encapsulation of organic-based concepts

Proof-of-principle of new conversion concepts

Processing, characterisation and modelling of especially nano-structured materials and devices

27Policy frameworks: Roadmap actions and milestones

Deploying PV according to the vision of this roadmap requires strong, consistent and balanced policy support. The four main areas of policy intervention include:

Creating a policy framework for market deployment today and the next decade, including tailored incentive schemes to accelerate market competitiveness

Improving products and components, financing models and training and education to foster market facilitation and transformation

Supporting continuing technology development and sustained R&D efforts to advance the cost and efficiency improvements outlined above

Improving international collaboration to allow for accelerated learning and knowledge transfer to emerging and developing countries

Achieving the ambitious deployment goals set and overcoming existing barriers will require targeted action all along the PV value chain (i.e. raw materials, module technologies, balance of system components), and throughout the lifecycle of product development from basic research to demonstration and deployment. It will also require measures fostering technologies enabling a large-scale deployment of PV, such as energy storage and grid integration technologies. This section presents a set of key actions intended to create an effective policy framework that will directly or indirectly support successful large-scale PV deployment. More detailed actions can be identified for the coming decade, which is the critical time period for policy action in order for PV to achieve the vision outlined in this roadmap. A number of important issues will remain relevant beyond 2030.

Regulatory framework and support incentives

This roadmap recommends the following actions: Milestones

Set long-term targets, supported by a transparent and predictable regulatory framework to build confidence for PV investments. The regulatory framework should specifically include financial incentive schemes to bridge the transition phase until PV has reached full competitiveness, and ensure priority access to grids over the longer term.

Begin 2010. Phase-out depends on when PV becomes fully competitive in a specific country; 2020 latest

Design and implement a regulatory framework to facilitate large-scale PV grid integration, including targeted Smart Grid based demonstrations for areas of high PV implementation.

Complete by 2020

Policy frameworks: Roadmap actions and milestones

Set predictable financial incentive schemes and regulatory frameworks

The high capital requirements for PV installations and manufacturing plants are clear, long-term, effective and predictable financial incentives (e.g. feed-in tariffs, feed-in premiums, portfolio standards, fiscal incentives, investment subsidies) and framework conditions (e.g. access to grids) for the next decade at least to provide sufficient investor confidence. Governments should establish long-term PV targets that can be implemented by such financial incentive schemes for market introduction and deployment. These schemes must be designed with long-term energy policy objectives in mind and should be steadily reduced over time to foster innovation and the development of the most cost-efficient technologies. As PV reaches grid parity, economic incentive schemes should evolve towards a market-enabling

framework based on net metering and priority access to the grid.

Providing economic support alone, however, is not enough. Non-economic barriers can significantly hamper the effectiveness of support policies. Administrative hurdles such as planning delays and restrictions, lack of co-ordination between different authorities, long lead times in obtaining authorisations and connection to the grid, are key barriers for PV deployment. Governments should address administrative barriers by ensuring coherence and co-ordination between different authorities and implementing time-effective and streamlined administrative authorisation procedures for PV systems.


To date, most PV incentive schemes concentrate on grid-connected systems. Stand-alone and rural PV systems are rarely supported, despite the fact that they may offer the most cost-efficient solution (e.g., replacing diesel generation). Dedicated and sustainable strategies to support off-grid

PV applications and services, in particular for rural electrification, need to be established. Schemes should take into account non-economic barriers as well as the need for new financing and business models, particularly in developing countries.

Establish regulatory frameworks that facilitate large-scale PV grid integration

Given its variable, non-dispatchable nature in distributed applications, PV presents new challenges for grid integration. In most areas of the world, PV has not yet achieved an electricity generation share larger than 1%, and can currently be absorbed by existing grids without any problems. However, with an increasing number of PV systems in place, interconnection and load management will become important issues. Grid accessibility and integration challenges may prevent PV from achieving this roadmaps vision if not properly addressed in the short term. However, better grid planning and management also bring opportunities. For instance, PV can reduce critical summer load peaks in some regions, reducing the need for high-cost peak generation capacity and new transmission and distribution investments.

In order to accomodate an increasing share of variable PV, a higher degree of system flexibility is required. This will require new ways of thinking about how electricity is generated and distributed and the development of new technologies that make it simple, safe, and reliable for solar electricity to feed into the grid. Flexibility16 can be increased both through market and transmission

16 Flexibility refers to the amount of quickly dispatchable

capacity generation, interconnection and storage that is

available to respond to fluctuations in supply and demand.

Source: Empowering Renewable Energies Options for Flexible

Electricity Systems, IEA 2008.

optimisation measures. Market measures include expanding markets to smooth overall variability and implementing demand response measures that better match demand with supply. Transmission optimisation measures include improved interconnection and adoption of advanced transmission and management technologies, including smart grids and metering and enhanced energy storage.

Addressing the issue of grid integration will require governments to act in the near-term, given the long lead times between planning and investing in new grid infrastructure and technologies. Regulators should initiate long-term planning aimed at increasing system flexibility and grid management. In areas with strong direct normal irradiation, planning the concurrent development of dispatchable CSP would allow for a larger amount of grid-connected PV.

In areas with a planned high use of PV generation, government should foster and co-finance smart grid demonstration systems, which would enable faster large-scale deployment of PV.

29Policy frameworks: Roadmap actions and milestones

Market facilitation and transformation

This roadmap recommends the following actions: Timeframe

Establish internationally accepted standards and codes for PV products and components to foster greater consumer adoption.

2010-2020

Identify new financing and business models for end-users and rural electrification to catalyse grid investments and storage solutions for the full-scale integration of PV.

2010-2020

Enhance training, education and awareness for skilled workforce along the PV value chain; expand outreach to residential and commercial customers.

2010-2025

Establish standards and codes

Standards, codes and certificates help create confidence and better handling of PV products. It is not only a question of safety and quality assurance but of improving the competitiveness of the industry by avoiding administrative hurdles and reducing unit costs. Standards, codes and certificates are needed for performance, energy rating and safety standards for PV modules and building elements; for grid interconnection; for quality assurance guidelines all along the value chain; and for the reuse and recycling of PV components. The development of an internationally agreed upon set of codes and standards will permit the increased deployment of a variety of PV technologies.

The IEA PVPS Implementing Agreement identified the following priorities for the development of standard and codes:17

i) PV industry internal standards for more efficient manufacturing

ii) PV as power supplier in interconnection issues

iii) PV as multifunctional products, e.g. BIPV.

17 These topics have been analysed within the IEA

Implementing Agreement on Photovoltaic Power Systems;

see www.iea-pvps.org

Foster new financing and business models

PV systems need considerable up-front investments, but once installed are low cost to operate. High initial investment costs are an important barrier for residential and small commercial customers and for off-grid applications. Investment barriers require innovative and uncomplicated financing approaches including the development of PV market and business models aimed at end-user service and efficiency. Today, most incentives are provided to PV grid-connected systems; PV systems in high-efficiency isolated homes are often not rewarded. Addressing this gap will require a shift in business models. One option that shows promise is the development of energy service companies (ESCOs) that own the system and provide an energy service to the end-user for a periodic fee. The user is not responsible for the maintenance of the system and never becomes the owner. Governments should

explore providing financial incentives to PV ESCOs for on-grid and off-grid applications.

The high cost of capital and limited access to funds exacerbates the investment cost challenge in the developing world. To overcome the barrier of high capital costs and encourage the widespread use of PV in rural and remote communities, new implementation models for financing and operating PV systems are needed. Several financing mechanisms are available (IEA PVPS 2008):

Direct (cash) sales: The end-user immediately becomes owner of the system.

Credit sales: The end-user obtains a credit from the PV dealer or from a third-party institution (possibly through micro-credit initiatives). Depending on arrangements, the end-user


ultimately becomes the owner and the PV system can be used as collateral against the loan.

Hire (lease) purchase and a fee-for-service model: The PV supplier/dealer or a financial intermediary leases the PV system to the end-user. At the end of the lease period, ownership may or may not be transferred to the end-user. Alternatively, a fee-for-service model based on an ESCO can also be applied.

Governments can also address the investment cost challenge by creating a market framework and/or mechanisms that foster investments in innovative grid and storage technologies. Time-dependent electricity tariffs (higher at peak load in summer), capacity value markets and ancillary PV markets have all shown promise and merit further exploration and adoption as appropriate.

Create a skilled PV workforce

Efforts are needed to increase the number of qualified workers for a growing solar industry along the value chain and the lifecycle of PV product development, from research to system installation and maintenance. A well-trained workforce is necessary to ensure technology development, quality installations, cost reductions, and consumer confidence in the reliability of solar installations. These activities should focus on building the capacity of educational institutions to respond to the increased demand for high-quality training for

solar installers and code officials.18 Governments are encouraged to provide training and education to create a skilled PV workforce along the full value chain. This involves developin

Documents

Technology Roadmap_ Solar Photovoltaic Energy-6110171e